Cellular telephones are well known in the art. Similarly, mobile pagers are well known in the art. While each art has advanced to a sophisticated level, there are still a number of shortcomings associated with each.
In relation to mobile pagers, a number of problems may arise. First, while a mobile paging unit may be reached almost anywhere in the country, that is obtain a signal, the pager itself does not know where it is located. Thus, to insure that it will be reached, the pager scans multiple frequencies to search for a signal. This scanning of multiple frequencies consumes excess energy.
Mobile pagers with national access capability operate at approximately 150 MHz. However, this frequency range is becoming overcrowded, as a result, pagers are beginning to utilize a 931 MHz frequency. These two frequency ranges are in separate bands and therefore require separate processing circuitry. Thus, if a pager is to utilize both bands, it requires additional circuitry which makes the pager more expensive and bulky.
Another problem related to mobile pagers relates to the inability of a user to identify the paging party by merely looking at the telephone number on the display.
There are also a number of problems associated with cellular telephone technology. First, cellular telephones are difficult to program to achieve particularized functions. Next, they do not provide online help.
To this juncture, mobile pagers and cellular telephones have been utilized concurrently, but never in a compact unitary package. A difficulty preventing such a combination relates to signal processing of the two types of signals. Cellular telephones operate at 800 to 900 MHz while mobile pagers operate at a frequency as low as 150 MHz.